1. Field of the Invention
The invention relates to an earphone apparatus, and particularly relates to an expandable multiple audio frequency earphone apparatus.
2. Description of Related Art
With the advancement of electronic technologies, electronic apparatuses have become an indispensable tool of our daily lives. Among the electronic apparatuses nowadays, whether an electronic apparatus provides a satisfactory audio-visual playing function is an important factor in determining whether such electronic apparatus is competitive on the market.
Regarding sound playing, various ways have been adopted to improve audio effect and quality in the conventional art. Nevertheless, the structures of conventional earphone apparatuses are normally fixed. Thus, the user has to purchase and carry around earphone apparatuses with different effects when having different needs. Therefore, the expense is higher and the use of the earphone apparatuses is not convenient, either.